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Topic: Another Keyboard Encoder (Read 1 time) previous topic - next topic

msholden

I have made a serial keyboard interface I would like to share with others. I would like to know what eles this project could use to make it better.  
Please see the attached PDF file
Thanks


CrossRoads

I'm a little confused - what is the purpose of using the LCD library here?

#include <LiquidCrystal.h>
// initialize the LCD library with the numbers of the Arduino pins used
LiquidCrystal lcd(3, 2, 4, 5, 6, 7); //LiquidCrystal(rs, enable, d4, d5, d6, d7)
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

FalconFour

#2
May 31, 2011, 10:35 pm Last Edit: May 31, 2011, 10:53 pm by FalconFour Reason: 1
Did 'ja a little favor here... cut the price in half by using one store instead of a bunch ;)










Part NumberDescriptionQuantityUnit CostTotal
171969IC,EDE1144,KEYPAD ENCODER DIP-181$5.19$5.19
169245SWITCH,KEYPAD,16 BUTTON, WITH 8 PIN MALE HEADER CONN.1$9.95$9.95
324962CRYSTAL,4.000MHZ,HC49/US,20PF1$0.59$0.59
97586@RESISTOR NET,10PIN,330OHM,2%,
125mW,ISOLATED
10$0.07$0.70
267944@RESISTOR NET,6 PIN,2.2K OHM
SIP,1/8W,2%,100PPM,COMMON
10$0.07$0.70
169288PCB,BLANK,SNGL SIDED,PHENOLIC,1$3.95$3.95
70755HEADER,VERTICAL,REC,1RW,8cont .100 (2.54mm),FEMALE HDR RECPT1$0.45$0.45
417682LED,MOUNTING HARDWARE, LOCKING HEADER,HORIZONTAL 3-PI1$0.25$0.25
Subtotal$21.78


Looks like a cool idea though! I could probably use something like this... plus, I haven't used one myself, but according to the "bus" schematic, a resistor net would be a lot more efficient than using individual resistors... well, shoot, now I think it out, the 330-ohm one might need an "isolated" net instead, but the 4.7k one (2.2k here, since 4.7k wasn't available but 2.2 should do just as well) is tied to ground so it should be perfectly suitable and simplify the PCB layout. :)

edit: Updated list with 330 ohm isolated resistor net (5x 330 ohm isolated resistors)
edit: Here's the part for 4.7k if you want to stick with 4.7k, it's a bit more expensive: http://www.jameco.com/webapp/wcs/stores/servlet/ProductDisplay?langId=-1&storeId=10001&catalogId=10001&productId=276172&

msholden

CrossRoads, The only reason I used the LCD to display the output of the keyboard is that I designed this keyboard for my bench buss for my Arduino.  It could be easily converted to serial.print();  Maybe it would make it simpler.  Thanks for your suggestion.

msholden

KE7GKP, Thanks for your input.  I have no intension on manufacturing and selling this.  I needed a keyboard interface for my Arduino and did not find one to meet my needs.  I just want to share this for food for thought.

msholden

FalconFour, Thank you for your time in helping me with better part selection. Do you mind if I work your price list into the document?  I had no production in mind just a one or two time project.  All of you guys are great in response.

FalconFour

Of course you can :) You'd have to make some adjustments to the PCB layout to make use of the resistor networks instead of single resistors, but it'd definitely make soldering easier. Just thought I'd help out with the parts a bit :)

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